The inventive subject matter relates generally to the field of experimentation and more particularly, to experimentation and optimization of the delivery of content to users within a digital network, such as the Internet. By the testing of marketing tactics, propositions, advertisements and offers businesses can optimize their campaigns and customer management procedures. For instance, an on-line retailer might test the effectiveness of different headlines and benefit statements in on-line advertising. An advertiser might test placing different advertisements across different advertising placements offered by different publishers. A, bank might test different contact and offer strategies in direct mail and outbound telemarketing to cross-sell financial services based on changes to a customer's account balances. A telecommunications company might test different offers and bundles of services to existing customers over the Internet and to their customer's mobile phones. Increasingly, businesses are advertising across a variety of mediums including search engines, banner advertising, contextual advertising, interactive TV, while completing transactions from their own web site. While the flow across these channels for a prospect may be seamless and driven optimal campaign elements across these different systems is challenging for businesses.